Die-casting apparatus



Dec. 22, 1964 F. E. ZEARBAUGH 3,161,918

DIE-CASTING APPARATUS Filed June 10, 1963 3 Sheets-Sheet 1 Fig/- IN V EN TOR. Hrs/20's E. knauy/z,

W MM Dec. 22, 1964 F, E. ZEARBAUGH DIE-CASTING APPARATUS 3 Sheets-Sheet 2 Filed June 10, 1965 INVENTOR. Franals E21araa /7, BY m Wtfiorweys.

Dec. 22, 1964 F. E. ZEARBAUGH 3,161,918

DIE-CASTING APPARATUS Fild June 10, 1963 3 Sheets-Sheet 3 United States Patent 3,161,918 DIE-CASTING APPARATUS Francis E. Zearbaugh, Rte. 3, Mannie, ind. Filed June 10, 1963, Ser. No. 286,762 18 Claims. ((31. 1842) The present invention relates to a die-casting apparatus and more particularly to a die structure so arranged as to minimize maintenance and repair requirements.

In conventional die-casting machines, a mold cavity is formed between a pair of closed die sections. In the usual instance, one of these sections is stationary and the other is movable into and out of engagement therewith. These die sections are provided with engageable parting surfaces, with the cavity being formed by separated surface portions in these parting surfaces when the mold sections are engaged. In parts being die cast, it is often necessary that the same be provided with a series of apertures, recesses, indentations and the like, and one convenient means for providing the same is through the use of core pins which are rigidly secured to one of the die sections. When the die sections close, the core pins project into the cavity and thereby become a part of the mold.

Various arrangements have been used in the past for securing the core pins to the die sections; however, they have all suffered from the same deficiency in that after a period of use, the core pins become worn and must there fore be changed. In order to change these, it has been necessary to take the die-casting machine out of operation, disassemble the die sections from the machine, make the necessary repairs in a tool and die shop or the like, then reassemble the new die section into the machine.

It has proven to be quite expensive and time-consuming in making these repairs, such that it becomes desirable to provide improvements whereby these deficiencies can be overcome.

It is therefore an object of this invention to provide in a die-casting apparatus an arrangement which facilitates the changing of parts with a minimum of time, effort and expense.

It is another object of this invention to provide a core pin assembly for a die-casting apparatus which requires only a few minutes time to change and does not require major disassembling operations in making the changes.

It is yet another object of this invention to provide an ejector pin holding assembly which is capable of being repaired or assembled and disassembled with a minimum of time, effort and expense.

Other objects will become apparent as the description proceeds.

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invent-ion taken in conjunction with the accompanying drawings, wherein:

FIG. l.is a side elevation, partly sectioned, of a diecasting machine which embodies the-features of the present invention;

FIG. 2 is a cross-section taken substantially along section line 22 of FIG. 1;

. FIG. 3 is an enlarged, fragmentary top. view, partly broken away and sectioned for clarity, of the machine of FIG. 1;

FIG. 4 is an enlarged, fragmentary sectional illustration taken substantially in the same plane as the view of FIG. 1 and showing the details of the construction in the die or mold sections;

FIG. 5 is still another enlarged, fragmentary sectional illustration of the arangernent of FIG. 4;. and

FlG. 6 is a partially sectioned view of a special tool used in disassembling the core pin assembly of FIG. 5.

3,lhi,9l8 Patented Dec. 22, 1964 Referring to the drawings, and more particularly to FIGS. 1, 2 and 3, a die-casting machine as shown in FIG. 1 comprises a stationary base 10, a stationary upstanding frame member 12 mounted on the base 10, and a horizontal hydraulic power cylinder 14 which is secured to the frame member 12. The power cylinder 14 has a piston rod 16 horizontally projecting therefrom which has secured to the outer end thereof a yoke is. Also mounted on the base it) and spaced toward the right from the upright member 12 is a stationary support 20 which carries an upright, stationary mounting block 22. Extending between and secured to the upright member 12 and the mounting block 22 are four (4) steel guide rods, which, as shown more clearly in FIG. 2, are located at the corners of an imaginary square. These rods 24 are parallel and preferably are provided with a smooth surface finish. A platen 26 which may be in the form of a flat block of steel is provided with four apertures which receive, respectively, the guide rod 24. The apertures, which are indicated by the numeral 28 in FIG. 3, are of such size as to receive slidably the rods 24 whereby the platen may be moved back and forth between the upright 12 and support 24 The platen 26 is operatively connected to the support 12 by means of a toggle linkage 30 which is connected to the yoke 13. As shown in FIG. 1, the platen 26 is retracted; that is, the platen is moved to its most leftward position. When the power cylinder 14 is operated, the piston rod 16 and yoke 18 are extended toward the right, which results in operation of the toggle 3% for forcing the platen 26 toward the right. This operation will be explained more fully hereinafter.

Mounted on the right-hand side of the platen 26 is a bracket 32 which carries on its right-hand end a mold section 34. This bracket 32 is hollow or in other words is square in shape for a purpose which will become obvious from the following description. Referring more specifically to FIGS. 3 and 4, the mold section 34 is conventional in the respect that it primarily consists of a substantially flat block of steel having a parting surface 36 which is provided with a cavity surface portion 38. In juxtaposition with the mold half 34 is a second mold section or half itl which is fixedly mounted on the stationary block 22. This mold half 40 is provided with a parting surface 42 and a cavity surface portion 44. The two mold halves 34 and 49 are arranged to be closed with the parting surfaces 36 and 42 engaged in sealing relation. The cavity surface portions 38 and 44 register with one another to provide a mold cavity into which molten metal may be injected. H

A conventional ram 46 (FlG. 1) is mounted on the base It) and carries a shot sleeve 43 which registers with a runner 50 (FIG. 4) in the mold half 34. This sprue passage 53 connects the ram with the cavity when the two mold halves 34 and 40 are closed.

The apparatus thus far described is conventional.

The mold half 34 is provided with four parallel bores 52, located at the corners of an imaginary square, which slidably receive four horizontal rods 54, respectively. These rods 54 extend beyond the opposite sides of the mold half 34 asshown. The left-hand-ends of theserods are secured to a flat, ejector plate assembly indicated generally by the numeral 56, this assembly being shown in more detail in FIGS. 4 and 5. The apertures 52, the rods 54 and the plate assembly 56 are made to such size, weight and strength as to support the plate assembly 56 for movement toward and away from the mold half 34. The reason for this will become apparent from the description which later follows.

The movable platen 26 is provided with four bores 58 spaced at the corners of an imaginary square, which are parallel. These bores 5% receive four elongated rods 60, respectively, for longitudinal sliding movement, the right-hand ends of these rods 60 being engageable with the rear side of the plate assembly 56 and the left-hand ends of these rods 60 being engageable with an upright, stationary bumper plate 62. This bumper plate 62 is suitably, rigidly secured to the machine frame and base 10. As shown in FIG. 3, all of the parts of the machine are in retracted position. In this position, the rods or bumper bars 60 are engaged at the left-hand ends thereof with the bumper plate 62, the ejector plate assembly 56 is engaged with the right-hand ends of the bumper bars 60, and the return pins 54 extend through the mold half 34 to the position shown. When the platen 26 is moved toward the right so as to close the mold, the bumper bars 60 are carried therewith and become spaced from the bumper plate 62. When the mold halves close, the return pins 54 engage the parting surface 42 of the mold half 40, thereby pushing these pins rearwardly and with them the ejector plate assembly 56. This in turn pushes the bumper bars 60 rearwardly, but enough space is provided so they will not contact the bumper plate 62. On the other hand, when the platen 26 is retracted, the dimensions on the parts should be such as to project the return pins 54 beyond the parting surface 36 ofthe mold half 34 as shown in both FIGS. 3 and 4.

A series of core pins are provided in the mold half 34 which have end portions which project into the mold cavity when the mold halves are closed. These core pins are parts of assemblies which will now be described, and since all of the assemblies are substantially identical, the description of one assembly will suffice for all.

Referring more specifically to FIG. 5, the assembly comprises a socket or cylindrical bore, in the mold half 34, of stepped diameter which consists of the larger diameter portion 64, an intermediate diameter portion 66, and a small diameter portion 68. The small diameter portion 68 opens through the cavity surface portion 38 while the rear end of the large bore portion 64 is closed. by means of a flat plate 70. A retaining member or cylindrical sleeve 72 is snugly, telescopically received by the bore portion 68 and is provided with an annular head 74 which engages the radial shoulder 76 between the intermediate and small bore portions 66, 68. Preferably, the diameter of the annular head 74 is sub stantially the same as that of the intermediate bore portion 66. vWhen the head 74 is seated against the shoulder 76, the length of the tubular sleeve 72 is such that it terminates flush with the surface 38.

Coaxially received by the large diameter bore portion 64 is a washer 78 which abuts against the head 74 and also a radial shoulder 80 which separates the large bore portion 64 from the intermediate boreportion 66, Also coaxially received by the bore portion 64 is a helical compression spring 82 which bears. at its right-hand end against thewasher 78 and at its left-hand end against plate 71}, This spring 82 bears against the washer '73 and sleeve 72 with a force greater than that exerted by molten metal which may be injected into the mold cavity during a casting operation. This, therefore, prevents the sleeve 72 from being moved leftwardly as viewed in FIG. Sunder the pressure of the molten metal in the cavity.

' The sleeve 72 is provided with a coaxial bore 84 which is uniformly tapered from end-to-end as shown. This taper divergestoward the surface '38 and in an operating embodiment ,of this invention the taper is made to su b.

V stantially /s inch for every twelve (12') inchesin length.

Frictionally inserted into the bore 84 isa core pin, in-. dicated generally by the numeral 86. This'core pin 86 is provided with a tapered shank'88 which has a taper which complements ormatches the taper of the bore 84"such that the surface of the shank 88 and the bore 4 64 and is secured to the plate by means of a suitable screw 92.

The core pin 86 is provided with an end portion or tip 94 which projects beyond the cavity surface 38 and which is tapered reversely to that of the shank S8. The shank 88 is longer than the tapered tip 94. Additionally, the tapers and materials of the pin portions 88 and 94 are such that the frictional grip of a cooled casting onto the portion 94 is less than the friction holding portion 88 in the sleeve 72.

In a working embodiment of this invention, the sleeve 72 and the pin 86 are made of steel. The surfaces 84 and 88 are sufficiently polished that when the pin 86 is inserted into the bore 84, the pin will become frictionally locked to the sleeve 72. Also, the degree of the tapering and the length of the tapering must be such as to provide this taper lock with enough strength to resist the opposing force when a casting is ejected. When it is desired to remove the pin 86 from the sleeve 72, the sleeve 72 is moved leftwardly until the left-hand end of the pin 86 engages the abutment pin 90. The sleeve 72 is then impacted with a suitable instrument so as to drive it leftwardly further thereby breaking the taper lock with the pin 86. The bore 84, of course, should be larger than the outer diameter of the pin 90.

A suitable tool for facilitating removal of the core pin 86 is shown in FIG. 6 and comprises a cylindrical member 96 which is provided with a socket 98, the diameter of the end 100 being such as will coincide with the right-hand end surface of the sleeve 72. This tool 96 is engaged with this end surfaceandthen impacted with a hammer so as to drive the sleeve 72 beyond a point at which the left-hand end of the pin 86 engages the abutment pin 90. This results in moving the sleeve 72 leftward relative to the pin 86 and breaks the taper lock therebetween. 7

After a period of time, operation of the die-casting machine will result in wearing the tip 94 of the core pin 86 to the point where the latter should be changed. The procedure just described is followed for breaking the taper lock and withdrawing, toward the right, the core pin 86. Another core pin identical in shape to the old one is inserted into the sleeve 72 to a point at which the tapered shank locks with the bore 84. This replacement procedure requires only a few seconds of time.

" The mold half 34, again as shown in FIGS. 4 and 5, is provided with four cylindrical bores 102 at the corners of an imaginary squarewhich slidably receive four ejector pins 104. These'ejector pins104 extend beyond the cavity surface portion 38 when the die half 34 is retracted to theposition shown in FIGS. 1, 3, 4 and 5. The left-hand ends of the ejector pins 104 are secured to the ejector plate assembly 56. This plate assembly comprises a rigid back-up plate 106 and a, cover plate 168, these two plates being secured together by means of suitable screws 11 0. A'stepped diameter bore is providedin the plate assembly, this bore comprising a larger diameter portion 112 and a smaller diameter portion 114.

, A suitable cylindrical or tubular sleeve 116 is slidably fitted into the smaller bore portion 114 and is provided with an annular head which engagesthe radial shoulder j 118 separating the bore portions 112 and 114, respectively, A' helical compression spring 120 is compressed between the head 122 of the sleeve 116 and the bottom 124 of the largerbore portion 112. An abutment pm 126 is secured at its, left-handend to the botto rn'124 of the bore portion. .J r V The. sleeve. 116 is provided with a tapered bore 128 which may be identicalto the bore 84 ofthe sleeve 72.

The left-hand end of the pin 104 may be tapered at 130. so as to frictionally fit the bore surface 128. g This POI? tion 130 maybe formed identically to the s-hfank88,

The left-hand extremity of the pm 104 at 1-32 is spaced fromthe right-hand end ofthepin 126 by-about 0.020'

m re; 7 T pa are lig ns ienna th th s spacing, the pin portion 136 frictionally engages and forms a taper lock with the sleeve 116. The sleeve 116 is made of such length that it never engages the lefthand side of the mold half 34.

In order to break the engagement between the sleeve 116 and the pin 104, a suitable tool or instrument is used to drive the sleeve 116 leftwardly more deeply into the bore or socket 112, thereby breaking the taper lock. The pin 194 is then simply removed and replaced by a new pin of the same configuration.

A cycle of machine operation in making a casting will now be explained. At the start of an operation, the machine is retracted to the positions shown in the drawings. In making a casting, the machine is actuated such that the power cylinder 14 operates to move the platen 26 rightwardly until the mold halves 34 and 40 close. The return pins 54 engage the parting surface 42 and are thereby retracted, moving the ejector plate assembly 56 rearwardly as well as the bumper bars 60. When the ejector plate 56 is moved rearwardly, the ejector pins 104 are retracted to a position at which they are flush with the cavity surface portion 38. Molten metal is then injected into the cavity formed between the surface portions 38 and 44 via the shot sleeve 48 and runner 51 this molten metal surrounding the tips 94 of the core pins 86. After the metal has solified, the power cylinder 14 is operated so as to retract the platen 26 which in turn retracts the mold half 34 from the mold half 4d. When the platen 26 has moved a short distance in retracting direction, the bumper bars 60 engage the bumper plate 62 and thereby force the ejector plate 56 toward the right while the mold half 34 is moving toward the left. This causes the pin 194 to project beyond the cavity surface 38 so as to knock the casting oif this surface. Since this surface 38 has a major projection thereon, and since the casting normally contracts thereunto in cooling, the casting will normally adhere to the mold half 34. it is the purpose of the ejector pins 1194 to knock the casting off this mold half.

Because of the taper lock between the core pins 86 and the sleeves 72, removal of the casting will not disturb the core pins 86. Thus, the casting operation may be repeated until the core pins are worn to the point that they need to be changed. The changing procedure has already been described.

Recapitulating, changing of the core pins 86 and ejector pins 194 is an extremely simple operation and serves to reduce the time in making repairs to die-casting machines as well as the attendant elfort and expense.

While 1 have described above the principles of may invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention.

What is claimed is:

1. In a die-casting machine, a die having a mold cavity therein, said die including two mold sections, means supportin said mold sections for relative movement selectively into and out of closing engagement with each other, said mold sections having parting surfaces which are sealingly engageable with each other, said mold cavity being defined by separated surface portions in said parting surfaces, respectively; a core pin assembly mounted in one of said mold sections and comprising a stepped diameter cylindrical bore which opens through the surface portion of said one mold section, said bore having large, intermediate and small diameter bore portions with the small bore portion opening through the last-mentioned surface portion, first and second radial shoulders separating said intermediate bore portion from the other bore portions, respectively, a cylindrical sleeve snugly telescoped into said small bore portion and having an annular head engageable with the second shoulder which separates the small bore portion from the intermediate bore portion, said sleeve terminating flush with said last-mentioned surface portion, a washer coaxially and slidably fitted in said large bore portion in engagement with said annular head and said first shoulder, a helical compression spring coaxially mounted in said large bore portion and forcibly bearing at one end against said washer for forcing the latter against said head, a bottom in said large bore portion, said spring bearing at its opposite end against said bottom, an elongated abutment pin coaxially positioned inside said spring and being secured at one end to said bottom, said sleeve having a tapered bore which diverges in a direction toward said last-mentioned surface portion, a core pin having a shank provided with a taper which matches the taper of said sleeve bore, said core pin being inserted into and engaged with said tapered bore, one end of said core pin being spaced from the other end of said abutment pin, the other end of said core pin being exposed to said mold cavity when said mold sections are closed.

2, The combination of claim 1 wherein the taper is about one-eighth inch in twelve inches axial length of said core pin, and the other end of said core pin having a reversed taper and extending beyond said last-mentioned surface portion.

3. The combination of claim 1 wherein said one mold section is of steel and said core pin is of steel.

4. The combination of claim 1 including an elongated ejector pin telescopically received by a bore which ex tends through said one mold section and opens through said last-mentioned surface portion, said ejector pin having first and second ends, said pin being movable to project the first end beyond said last-mentioned surface portion while the second end is, disposed beyond a side of said one mold section opposite said last-mentioned surface portion, an ejector plate, means mounting said ejector plate for relative movement toward and away from said mold section side, a second bore in said ejector plate having large and small diameter portions, the second small diameter slidably receiving a second cylindrical sleeve which extends beyond said ejector plate toward said mold section side, a head on said second sleeve engageable with a shoulder which separates the second large and small bore portions, a second helical spring coaxially received by said second large bore portion and being compressed between said second sleeve head and the bottom of said large bore portion, a second abutment pin coaxially positioned inside said second spring and secured at one end to the bottom of said second large bore portion, said second sleeve having a tapered bore which diverges toward said one rnold section, said second ejector pin end being engageably inserted into said second sleeve bore and having a taper which matches the taper of said tapered bore, the extremity of said second end being spaced from the other end of said second abutment pin.

5. In a die-casting machine, a die having a mold cavity therein, said die including two mold sections, means supporting said mold sections for relative movement selectively into and out of closing engagement with each other, said mold sections having parting surfaces which are sealingly engageable with each other, said mold cavity being defined by separated surface portions in said parting surfaces, respectively; a core pin assembly mounted in one of said mold sections and comprising a stepped diameter cylindrical bore which opens through the surface portion of said one mold section, said bore having large, intermediate and small diameter bore portions with the small bore portion opening through the last-mentioned surface portion, first and second radial shoulders separating said intermediate bore portion from the other bore portions, respectively, a cylindrical sleeve snugly telescoped into said small bore portion and having an annular head engageable with the second shoulder which separates the small bore portion from the intermediate bore portion, said sleeve terminating flush with said last-mentioned surface portion, a helical compression spring coaxially mounted in said large bore member, said opening and cross-section.

portion and forcibly bearing at one end against said head, a bottom in said large bore portion, said spring bearing at its opposite end against said bottom, an elongated abutment pin coaxially positioned inside said spring and being secured at one end to said bottom, said sleeve having a tapered bore which diverges in a direction toward said last-mentioned surface portion, a core pin having a shank provided with a taper which matches the taper of said sleeve bore, said core pin being inserted into and engaged with said tapered bore, one end of said core pin being spaced from the other end of said abutment pin, the other end of said core pin being exposed to said mold cavity when said mold sections are closed.

6. In a die-casting machine, a die having a mold cavity therein, said die including two mold sections, means supporting said mold sections for relative movement selectively into and out of closing engagement with each other, said mold sections having parting surfaces which are sealingly engageable with each other, said mold cavity being defined by separated surface portions in said parting surfaces, respectively; a core pin assembly mounted in one of said mold sections and comprising a stepped diameter cylindrical bore which opens through the surface portion of said one mold section, said bore having large and small diameter bore portions with the small bore portion opening through the last-mentioned surface portion, a radial shoulder between said bore portions, a cylindrical sleeve snugly telescoped into said small bore portion and having an annular head engageable with said shoulder, said sleeve terminating flush with said last-mentioned surface portion, a helical compression spring coaxially mounted in said large bore portion and forcibly bearing at one end against said head, a bottom in said large bore portion, said spring 7 bearing at its opposite end against said bottom, an elongated abutment'pin coaxially positioned inside said spring and being secured at one end to said bottom, said sleeve having a tapered bore which diverges in a direction toward said last-mentioned surface portion, a core pin having a shank provided with a taper which matches the taper of said sleeve bore, said core pin being inserted into and engaged with said tapered bore, one end of said core pin being spaced from the other end of said abutment pin, the other end of said core pin being exposed to said mold cavity when said mold sections are closed. a

7. In a die-casting machine, a die having a mold cavity portion thereof, a retaining member snugly telescopically received by said socket and having an end surface which terminates flush with said last-mentioned surface portion,

means yieldably holding said member against movement in a direction away from said last-mentioned surface portion, a straight elongated opening through said member which opens'through said last-mentioned surface portion, said opening having a uniform taper which diverges toward said last mentioned surface portion, a core pin having a shank engageably inserted into said tapered opening, said shank having a taper which matches, the taper of said'opening,

one end of said coreipin projecting beyond said last-mentioned surface portion, and said one mold section having abutment means thereon which is spaced from but engageable by the other end of said core pin.

8. The combination of claim 7 wherein said socket, said said shank are all circular in cated of the same metal, and said one end of said core pin is tapered oppositely to that of said shank and is shorter than said shank.

10. In a die-casting machine, a mold section having a parting surface which is provided with a cavity surface portion, a core pin assembly mounted in said mold section and comprising a socket in said mold section which opens through the surface portion thereof, a retaining member snugly telescopically received by said socket and having an end surface which terminates flush with said surface portion, means yieldably holding said member against movement in a direction away from said surface portion, a straight elongated opening through said member which opens through said surface portion, said opening having a uniform taper which diverges toward said surface portion, a core pin having a shank engageably inserted into said tapered opening, said shank having a taper which matches the taper of said opening, one end of said core pin projecting beyond said last-mentioned surface portion, and said mold section having abutment means thereon which is spaced from but engageable by the other end of said core pin.

11. .In a die-casting machine, a mold section having a parting surface which is provided with a cavity surface portion, an elongated ejector pin telescopically received by a bore which extends through said mold section and opens through said surface portion, said ejector pin having first and second ends, said pin being movable to project the first end beyond said surface portion while the second end is disposed beyond a side of said mold section opposite said surface portion, an ejector plate, means mounting said ejector plate for relative movement toward and away from said mold section side, a bore in said ejector plate having large and small diameter portions, the small diameter portion slidably receiving a cylindrical sleeve which extends beyond said'ejector plate toward said mold section side, a head on said sleeve engageable with a shoulder which separates the large and small bore portions, a helical spring coaxially received by said large bore portion and being compressed between said sleeve head and the bottom of said large bore portion, an abutment pin coaxially positioned inside said spring and secured at one end of the bottom of said large bore portion, said sleeve having a tapered" bore which diverges toward said one mold section, said second ejector pin end being engageably inserted into said sleeve bore and having a taper which matches the taper'of said tapered bore, the extremity of said second end being spaced from the other end of said abutment pin.

l2. A'device as described herein comprising a body having a surface, a socket provided in said body-which opens through said surface, a retaining member slidably received by said socket, means holding said member against movement in one direction away from said surface, an elongated opening through said retaining mem her which extends in'a direction substantially parallel to the sides of said socket, said opening having a uniform taper which diverges outwardly of said socket, a pin having a shank engageably inserted intosaid tapered opening, said shank having a taper which matches the taper of said opening, and abutment means in said socket which is engageable with the smallerend of said shank for 9. The combinationof claim wherein'said socket, said 7 member, said opening and said shank areall circular in cross-section, said member and said core pin are fabri moving-said pinirelative to said member.

13. The device of claim 12 including means yieldably urging said member in a direction outwardly of said socket. 7 1 V 14. The device of. claim l2 including means yieldably urging said member in a direction outwardly of said socket, said abutment means being. normally spaced from urging said member ina direction outwardly of said socket, said abutment "means being engaged with said -smaller end' whereby movement of said member more 3 deeply into said socket will result in relative movement between said member and said pin.

16. In a die-casting machine, a die having a mold cavity therein, said die including two mold sections, said die including means supporting said mold sections for relative movement selectively into and out of closing engagement with each other, said mold sections having parting surfaces which are sealingly engageable vn'th each other, said mold cavity being defined by separated surface portions in said parting surfaces, respectively; a. core pin assembly mounted in one of said mold sections and comprising a socket in said one mold section having an opening which communicates with the surface portion thereof, said opening having a uniform taper which diverges toward said last-mentioned surface portion, a core pin having a shank engageably inserted into said tapered opening, said shank having a taper which matches the taper of said opening, one end of said core pin projecting beyond said last-mentioned surface portion, and abutment means which is selectively engageable with the other end of said core pin for moving the latter in one direction in said opening.

17. In a die-casting machine, a mold section having a parting surface which is provided with a cavity surface portion, a core pin assembly mounted in said mold section and comprising a socket in said mold section having an opening which opens through the surface portion thereof, said opening having a uniform taper which diverges toward said surface portion, a core pin having a shank engageably inserted into said tapered opening, said 1% shank having a taper which matches the taper of said opening, one end of said core pin projecting beyond said last-mentioned surface portion, and abutment means which is selectively engageable with the other end of said core pin for moving the latter relative to said socket.

18. In a die-casting machine, a mold section having a parting surface which is provided with a cavity surface portion, an elongated ejector pin telescopically received by a bore which extends through said mold section and opens through said surface portion, said ejector pin having first and second ends, said pin being movable to project the first end beyond said surface portion While the second end is disposed beyond a side of said mold section opposite said surface portion, an ejector plate, means mounting said ejector plate for relative movement toward and away from said mold section side, a bore in said ejector plate having a taper which diverges toward said one mold section, said second ejector pin end being engageably inserted into said bore and having a taper which matches said taper of said tapered bore, an abutment means which is selectively engageable to said second end.

References (Cited in the tile of this patent UNiTED STATES PATENTS 632,246 Cooper Sept. 5, 1899 2,711,568 Palmer et a1. June 28, 1955 2,860,376 Graves et al Nov. 18, 1958 3,013,308 Armour Dec. 19, 1961 

17. IN A DIE-CASTING MACHINE, A MOLD SECTION HAVING A PARTING SURFACE WHICH IS PROVIDED WITH A CAVITY SURFACE PORTION, A CORE PIN ASSEMBLY MOUNTED IN SAID MOLD SECTION AND COMPRISING A SOCKET IN SAID MOLD SECTION HAVING AN OPENING WHICH OPENS THROUGH THE SURFACE PORTION THEREOF, SAID OPENING HAVING A UNIFORM TAPER WHICH DIVERGES TOWARD SAID SURFACE PORTION, A CORE PIN HAVING A SHANK ENGAGEABLY INSERTED INTO SAID TAPERED OPENING, SAID SHANK HAVING A TAPER WHICH MATCHES THE TAPER OF SAID OPENING, ONE END OF SAID CORE PIN PROJECTING BEYOND SAID LAST-MENTIONED SURFACE PORTION, AND ABUTMENT MEANS WHICH IS SELECTIVELY ENGAGEABLE WITH THE OTHER END OF SAID CORE PIN FOR MOVING THE LATTER RELATIVE TO SAID SOCKET. 